Trailer coupling



Nav. 9 192e. 1,606,242

G. L. KNOX 1 TRAILER COUPLING Filed March 30 1925 3 Sheets-,Sheet l fzyf.

s-Shest I Nov. 9 1926.

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Filed March 30 Patented Nov. 9, 1926.

.TRAILER @Alanna L. Knox, or nos ANGELEs, oIiIronNIA, AssIGNon YTo UTILITY TRAILER M nnurrionnrns"coi/Enna', "A ooItPonATIon or CALIFORNIA.

coUPLInG.

application inedy March 30, 1,925. Serial No. 19,223.'

This invention relates. senela11yi0-tiaile1. couplings and is especially .applicable `to couplings adapted 4to two wheeled trailers, the forward ends of which are supported by the. towing vehicle.

` All tractors havea ireactiontendency.to tip up iii from, .this tendency .beiiisespscially' marked in tractors of a certain type. In my coapendingapplication,for patent on trailer couplingsffiled April 9, 1923, Serial No. 630,752, and in IBatent No. 1,524,5Q3, January 27, 1925, 011 traileiceuplnas, isf Sued jointly t0 Harold @Bennett and on self, is shown a Inethed ofcounter-acting this rearingfup tendencyof tractors by coupling trailers thereto in a certain man? ner. Briefiy described, this method Vcoinprises coupling means .whereby the ,dra-ft connection is below the rear axle of lthe tractor and the application of the trailer load is at a point below,ibut.not behind said axle. How this effects thedesired resultis fully set up in said application'and patent. In both the structures disclosed in said papers, there are provided .a separate V,draft tongue and load vimposing member, though it is to be noted that in the structure -of ,the pending applica-tion theeffective point of draft connection and the yeffect-ive .pointof/ load imposition are one and the same. In both cases there is `a swinging weight `supporting structure adapted to pivotallyengage the tractor at a point below, and not 'beliinchthe drive axlethereof, whereby the weight imposition member yis. capable `of .bei ing automatically ,elevated Vand Vmounted thereon as the trailer entersy intocoupled engagement with the towing vehicle,.thus lifting from vthe ground the skids orsmall wheels provided at the fore end ofthe trailer for supporting it when the trailer is dis-associated fromthe towing vehicle. A specific point of difference between the structures disclosed in the two papers in this: in the applicatiointhe swinging structure is permanently carriedby 'the-,towing vehicle, while in the patented device the swinging structureis carried permanently by the weight imposition tongue of the trailer.

AThe present invention has all the features of said prior application .and patent as tofthe selffmounting feature (characterized .by a swinging l weight Vsupporting structure) point of effective draft connection and point of loadv imposition, but goes further in that all this is accomplished with the use of but a single tongue extending between trailer and tractor. .It embodies the distinctive feature of the structure disclosed inthe pen-ding application as to aveoinmon point of effective draft application and weight imposition'. As a further feature, this cornmon .pointiis located so it is below andnormally ahead of the rdriving Vaxle of the tractor,rin place of-.being normally directly beneath said axle, the trailer weight thus constantly exerting 'a force .tending tofdepress the forward end ofthe tractoigfwhile any tendency of the :forward end of the tractor to rise is opposed justin proportion to that tendency. f

VIii-Patent No. 1,524,504 `ontrailer couplings issuedjjointly to Harold C. Bennett and myself January 27, -l\9 25,jthere fis disclosed 4a type of coupling wherein a single tongue on the trailer serves as a draft con,- nectlile and 'weight Imposition meinbenfthe effective lpoint, of connection -and jweight imposition `being belowv the-driving laXle4 of the tractor. Howev'er, the single tongue Adirectly engages the tractor below saidrear axle. and ismounted-Vby riding up 'an inclined plane stationarily'mounted on ythe tractor, ratherthan engaging a swinging,

structure ata pointe-beve theeommonpoint ofdraft connection and load imposition and being elevated by virtue of 'such engage nient, as is true of the present invention. One of the chief advantages of the present inventionover' the struct-ure .disclosed in the lastfnamed patent resides inthe fact fthatthe point of tongue engagement maybe above the driving Iaxle of theQtractor `while the effective point vof vdraft connection and weight imposition may be well below said axle, themajor .portion of the conplingthus being'digsposed where it is easily accessible and where road ,clearance ,does nothaye to be taken into account.

There are rcertain features of construction whereby l the necessaryflexibility v.between tractor and trailer is provided but these maybediscu'ssed to better advantage in the following detailed.description, reference being ,made-to .the accompanying drawings, in which:`

lis a longitudinal,.elevation showing a tractor and trailer coupled by my device;

2 is a view similar to 151g. 1 but showthe tractor and trailer uncoupled; i `s a fragmentary plan view showing the trailer tongue applied to carried portion of tne coupling, the rear axle and driving wheels, only, of the tractor Fig. is section on line /l-a of Fig. 3; Fig. 5 is a section on line 5-5 of Fig. Ll,

' trailer Fig. 6 is a section, partly in elevation, on line t-6 of Fig. il, but s'hou'fing the parts in the relative position shown in 2;

7 is an enlarged, fragmentary section on line 6-6 of Fig. 8; anc

Fig. 8 is a section on line c3- 8 of Fio'. 7.

ln the drawings, numeral 10 designates generally a semi-trailer having traction wheels 11 and forward wheel or wheels 12, which latter are adapted to support the forward end of the trailer when uncoupled from the towing vehicle 2). W ien towing vehicle and trailer are coupled, the forward end of the trailer is preferably elevated sufficiently to clear wheel 12 from the ground (Fig. 1).

Trailer 10 has a tongue 13, and in the embodiment of the invention here illustrated the tongue has a cylindrical terminal piece 14C bolted thereto, there being a peripheral groove 15 in the piece near the end of the tongue, proper. It is to be understood, however, that this specific end formation of the tongue is not essential to the invention, considered in its broader aspects, as will be made apparent later in the specification, and therefore this illustration and description of a specific structural feature is not tolbe considered as limitative on the invention, except as specifically so set forth in the claims. This remark applies with equal force to the drawings illustrating the rest of the structure as well as the following .description thereof. t

Numeral 16 indicates a towingl vehicle, a rear wheel drive tractor, for instance, having guiding wheels 17 and rear drive wheels 18, the latter being on drive axle 19. Differential casing 2O is located centrally of axle housing 21, the housing and tractor body, of course, moving as one about the rear axle when the forward end of the tractor is elevated or lowered, as when traveling over uneven ground or starting up or down grade.

For mounting and coupling to the trailer tongue, I have provided on the tractor a supporting structure adapted to swing on a horizontal axis located below the rear axle and extending substantially in parallelism therewith. For instance, I provide arms or hangers 22 at opposite sides of the differential casing, these hangers preferably being incassa clamped to axle housing 21 near wheels 18. Arms 22 support horizontally extending pivot pins 23 below and, preferably, normally forward 0f the rear axle, as shown. The significance of this pivot location will be made apparent later.

Pivoted on each pin 23is a yoke 2a having two arms that extend upwardly to points above the rear axle. Member bridges the differential casing and connects the four yoke arms. Now the swinging support structure so far described as consisting of yoltes 24 and bridge 25,2is especially adapted to presentday tractor construction wherein the dierential housing is situated midway between the rear wheels. rlhe bulk of the differential casing and its nearness to the ground more or less precludes the disposition of the pivot pins below the differential casing, that is, centrally of the tractor, it consequently being desirable to malte the point of support connection as close to the wheels as possible, where there is minimum interfering structure on the tractor. rEhe spaced and connected yoke structure lends itself particularly well to conditions as they now exist but it is to be understood the invention, in its broader aspects, contemplates` the use of a single, swinging yoke or member pivot-ally connected to the axle housing midway of the rear wheels, where tractor construction renders such an arrangement permissible and desirable.`

On top bridge 25 is a turn-table arrangement 26 adapted to be engaged by the trailer' tongue. l/Vhile any type of table suitable to the purpose lies within the scope of my broader claims, l will describe in some de tail the arrangement illustrated to give a clear understanding of its operation.

rl`he table portion of the device is plate 27 integral with or stationarily mounted on bridge 25. The fore and aft edges 28 of the plate are arcuately cut about a common vertical axis A (Fig. 5) while the parallel sides 29 of the plate are chordal.

Tongue engagement member 30 includes an elongated channel 81 of arcuate crosssection having vertically spaced, inturned flanges 32 provided at each end. Flanges define between them ways 33 adapted to talte plate edges 28, the flanges preferably being arcuately extended beyond the sides of channel 31 as at 34 in order to give ample f bearing surface. lt will be evident from the above that memberrBO may be swung over plate 27 about axis A, and that when member 30 is swung through an angle vof approximately from the position of Fig.

3, flanges 32 clear the plate, due to the chordal characteristics of sides 29, and separative vertical movement of the channel may be set up to disasseinble the turn-table. lt is preferable, though not necessary, that channel 31 be provided With a depending lll? the tractor.

centering stud 35, with its axis coincident with axis A, adapted to rotatev within a central bearing bore 36 in plate 27.

Channel 31 is closed at one end 37 and has a portion 88, of arcuate cross-section, overhanging the channel grooveat that end, an end socket 39 being thus defined.

TWhen the trailer is uncoupled, swinging support yokes 24 are in the position of Figs. 2 and 6, the swinging structure being limited in its movement in a counterclockwise direction, as viewed in these. figures, by engagement with the differential casing, for instance. Table 27 and channel 8O thus inoline downwardly and rearwardly and are at such a height above the ground that the forward terminal of the trailer tongue is in a horizontal plane intersecting the table plane near its lower edge. Hence, when the tractor is backed towards the trailer, or the trailer advanced towards the tractor, tongue terminal 14 may be guided intol the groove of channel 8O and rides up the inclined plane, thus elevating the forward end of the trailer. As thenose of the trailer passes axis A, yokes 24 and associated parts swing forwardly on pivot pins 23, bringing table 27 into horizontal position, continued relative approaching movement between tractor and trailer moving the nose of terminal 14 into the end` socket 39. An arcuate strap or keeper 40, pivoted on table 27 at 4l is swung over terminal 14, as shown in Figs. 7 and 8, an internal annular flange 42 on the collar being adapted to enter terminal groove l5. A bolt 44 and wing nut 45, or other suitable holding devices, are adapted to hold the keeper strap releasably in operative position.

It will be evident how flange 42 prevents accidental separative longitudinal movement between channel 3l and terminal 14 without preventing relative rotation thereof, this provision for rotation taking care of relative side tipping movement of tractor and trailer when passing over roads irregular in crown cross-section.

Straps 38 and 40 hold terminal 14 and channel 3l against spreading apart vertically and hold the swinging support structure against fore and aft swinging movement away from said terminal and out of operative position, thus limiting the swinging movement of the structure with relation to The pivotal mounting of channel 8l on plate 27 allows relative movement between tractor and trailer when the direction of travel is changed. By reason of this rotatable mounting, it is found possible to mount the trailer tongue automatically in the manner described even though the tractor and trailer are out of longitudinal axial alinement.

Now it will be observed .that the effective point-of draft/connectionand the effective point oftrailer weight. imposition is at the pivotal connection between yokes 24y and the rear axle housing, that is, at pivot points 23which are below and preferably forward of rear axle 19'. There is, therefore, a contively a force tending to oppose that elevation.

It is to be understood that the drawings and description are to be considered merely as illustrative of and not restrictive on the broader claims appended hereto for various changes in design,structure-and' arrangement may be made without departing from-the spirit and scope of said claims.

l claim: i

l. In a coupling device adapted to couple a trailer to a towing vehicle havingr a rear driving axle, meansengageable by the trailer tongue at a point above said drivingraxle for'supporting the trailer tongue on the towing vehicle and normally applying .the weight of the trailer to theI towing vehicle at a point below an-d ahead of said driving axle.

2. In a coupling device adapted toy couple a trailer to a towing vehicle having rear driving axle, means connected to the tractor and engageable by the trailer tongue ata point above said drivinga'xle for supporting the trailer on the towing vehicle and applying the weight of the trailer to the Ytowing vehicle at a point below said driving axle, and means adapted to hold said tongue and engafgeable means against relative separative movement whereby the tongue and member provide draft connective means between the tractor' and trailer, the effective point of draft'connection being at said point of weight application.

3. In a coupling device adapted toucouple a trailer to a to vl'ing vehicle having a rear driving axle, means connected to the tractor and engageable by the trailer tongue/at a Joint above said driving axle for supporting the trailer on the towing vehicle auf. applying the weight of the trailer to the towing vehicle at a point below said driving axle, and releasablemeans adapted to hold Asaid tongue and engageable meansvagainst relative separative movement whereby the tongue and member provide draft connective means between thev tractor and'trailer, the effective point'of draft connection being at saidpointof weight application.

4. Ina coupling device vadaptedqt'o couple Y a ltra-iler yto a'towing vehicle havinga yrear Url driving axle, means connected to the tractor and engageable by the trailer tongue at a point above said driving axle 'for support ing the trailer on the towing vehicle and applying tne weight ot the trailer to the towing vehicle at a point below and normally aheadL of said driving aille, and means adapted to hold said tongue and engageable means against relative separative movement whereby the tongue and member provid-e drait connective means between the tractor and trailer, the ell'eetive point ot draft connection being at said point oi weight application.

5. A device for raising and supporting a trailer tongue on a towing vehicle having a rear axle, embodying a structure swinging on a horizontal axis located below and normally ahead of the rear axle and having a part engageable by the trailer tongue whereby the tongue is supporte l.

6. A device for raising and supporting a trailer tongue on a towing vehicle having a rear axle, embodying a structure swinging on a horizontal axis located below and normally ahead of the rear axle and having a part extending above said axis and engageable by the trailer tongue whereby the tongue is supported.

7. A -device for raising and supporting a trailer tongue on a towing vehicle having a rear axle, embodying` a struc-ture swinging on a horizontal axis located below and norinallyl ahead of the rear axle and having a part extending above said axis and engageable by the trailer tongue whereby the tongue is supported, and eoacting means on the tongue and swinging` structure adapted to hold them in engagement.

8. A' device for raising andsupporting a trailer tongue on a 'towing vehicle having a rear axle, embodying a. structure swinging on a horizontal axis located below and normally ahead ot the rear axle and having a part extending above axis and engageable by the trailer' tongue whereby the tongue is supported, and coacting means on the tongue and swinging structure adapted to hold said structure against swinging' relative to the tongue.

9. A. device i'or raising and supporting a trailer tongue on a towing vehicle having a rear axle, embodying a structure swinging on a horizontal axis located below and nor-V mally ahead ot the rear axle and having a part extending above said axis and engageable by the trailer tongue whereby the tongue is supported, and coacting means on the tongue and swinging structure adapted to hold said structure releasably vagainst swinging relative Vto the tongue.

l0. A device `for raising and supporting a trailer tongue on aV towing vehicle. having rear axle, embodying a structure swinging Von a horizontal axis located below the rear axle and having a part extending above said axis and Vengageable by the trailer tongue whereby the tongue is supported, and coasting means on the tongue swinging structure adapted to hold said structure 7u against swinging relative to the tongue in a manner whereby said tongue is adapted to limit the swinging movement of' the swinging structure with relation to the towing vehicle.

il. e. device ior raiing and supporting a trailer tongue on a towing vvehicle having a rear axle, embodying a structure swinging on a horizontal axis located below the rear axle and having a part extending above said axis and engageable by the trailer tongue whereby the tongue is sup aorted, and coacting means on the tongue and .swinging structure adapted to hold them inV engagement, said tongue being axially revoluble on said structure when they are in engage ment, Y

l2. device i'or raising and supporting a trailer tongue on a towing vehicle having a rear axle, embodying a structure swinging on hor ntal axis located below and normally ahead olf the rear axle and having a part extending above said axis and engageable by the trailer tongue whereby the tongue is supported, and coa-sting means on the Longue and swiiiging structure adapted to hold them in engageinent,-said 'tongue being axially revoluble on and capable of swining horizontally with Vrespect to said structure when they are in engagement.

lil. A coupling device adapted to couple a trailer to a wheeled towing vehicle, coniprising a. swinging structure adapted 'to swing on a horizontal axis on the towing vehicle, said axis being substantially parallel to and below the axis of rotation of the rear wheels oi said vehicle, and means on the swinging structure adaptet to take a trailer tongue, said means including horizontally arranged turn-table device adapted to ceive the tongue.

la. i coupling device adapted to couple a. trailer to a towing vel lele, (,fomprising a swinging structiue adstptod to fi" horizontal axisron the towing ve means on the swinging structure take a trailer tongue, said me J horizontally arranged turn-table device adapted to receive the ton in a manner to allow axial rotation ot .id tongue.

l5, A coupling device adapted to couple a trailer to a wheeled towing vehicle, coinprising a sii/*inging structure adapted to swing on a horizontal axis on the towing vehicle, said axis being substantially parallel to Vand below the axis ot rotation. et the rear wheels of said vehicle, means on the swinging structure adapted to take a trailer tongue, said means inclu-ding a horizontally arranged turn-table Vdevice adapted to 1re;

lll)

oeive the tongue, and releasable means adapted to hold the tongue againstV separative movement with respect co-said device.

16. A coupling .device adapted to couple a trailer to a wheeled towing vehicle, comprising a swinging structure adapted to swing on a horizontal axis on the towing vehicle, said axis being substantially parallel to and below the axis of rotation of the rear wheels oi said vehicle, and means on the swinging structure adapted to take a trailer tongue, said means including an upwardly opening channel member pivotally connected to the supporting structure on an approximately vertical axis, the terminal of the trailer tongue being receivable by the chan-V nel groove, and a releasable keeper adapted to hold said terminal in said groove.

17. A coupling device adapted to couple a trailer to a towing vehicle, comprising a swinging structure adapted to swing on a horizontal axis on the towing vehicle, and means on the swinging structure adapted to take a trailer tongue having a cylindrical terminal, sai-d means including an upwardlyv opening channel member of arcuate cross section and being pivotally connected to the supporting structure on an approximately vertical axis, the terminal ofA the trailer tongue being receivable by and being` axially rotatable within the channel groove. 'and a releasable keeper adapted to liold said terminal in said groove.

18. In a coupling device adapted to couple a trailer to a towing vehicle having a' rear driving axle, means connected to the t actor an-d engageable by the trailer tongue at a point above said driving axle for supporting the traileion the towing vehicle and applying the weight of the trailer to the towing' vehicle at a point below said driving axle, yand means adapted to hold said structure adapted to hold said structure against swinging relative to the tongue.

In witness that I claim the foregoing I have hereunto subscribed my lname this 17 day of March 1925. y i

GARNIER L. KNGX. 

